Things like square footage, type of tile and project complexity are the main drivers of tile installation costs.

Square footage

Most tile professionals base the price of tile installation on the square footage of your project. The cost per square foot varies, depending on:

• Where the tiles are installed (kitchen, bathroom, backyard, etc.)
• The size and condition of the surface area to be tiled
• The size of the tiles themselves (smaller tiles cost more, larger tiles less)

A general rule of thumb when it comes to square footage: the larger the project size, the lower the cost per square foot. Determining the square footage of your project is important for getting an accurate quote from tile contractors. First, measure the length of the floor, then multiply that number by its width. For example, a 10-foot by 11-foot room = 110 square feet.

It's not a bad idea to overestimate the square footage on a project because contractors might need a little extra to allow for broken tiles or unusual shapes. Here's a sample of national average pricing for common room sizes.

Type of tile

Tile flooring prices range from under $1 to well over $50, depending on the material, manufacturer and demand. Selecting tiles with a higher average cost per square foot affects the total cost of a project. In addition, handmade or nonuniform tiles cost more to install because they need to be "back buttered” – a process that involves applying mortar to the uneven components of the back of the tile to ensure it lies flat for even flooring. This adds to labor cost.

Repair work

If a tile installation project is in an area that has had a leak, mold damage or a structural integrity issue, the damage needs to be addressed before you can install new tile flooring. Some tile contractors are able to do this work for you (it will cost extra), but depending on the extent of the damage, you may need to hire specialists.

If the needed repairs aren't apparent until the original backsplash or flooring has been removed, your quote will likely increase to encompass this new scope of work. Contractors aren't trying to trick customers when this occurs; in any construction or remodel project that includes demolition, there is always the chance of uncovering surprises such as dry rot. Communicate clearly with your professional about any pricing changes to make sure you understand what repairs are needed and what the cost will be.

Surface prep

In general, the less time a tile flooring job takes, the lower your cost will be. Even if you're no tile pro, you can see that it's much quicker to install tile on smooth, even flooring than on lumpy areas that need to be sanded out first. Tile installation jobs over smooth surfaces typically cost less because the installer needs to do less prep work before laying the tile. Uneven floors, old flooring that must be removed, and walls or counters that require backer board installation or additional steps beyond the standard preparation may increase overall cost per square foot.

Location

Your geographic location will affect floor tile installation costs. Tile professionals in larger cities and regions with a higher cost of living typically charge higher rates for services. This is because it costs more money to run a business in an expensive area where insurance costs are higher, employee labor rates cost more, and vehicle maintenance and fuel are more expensive. In addition, very moist or coastal environments can be more challenging for tile installation, so costs may be higher in these regions as well.

Size

Most floor tiles come as squares that vary in size from 4 x 4 inches to 24 x 24 inches. Tiles can also come in other shapes and sizes, including hexagonal, octagonal and rectangular subway tiles. Small or unusually shaped tiles may require more time and expertise, increasing the overall cost of tile floor installation. Large tiles are far less complex and cheaper to install.

Let's take a closer look at your the options for your new tile floor and how they differ.

• Ceramic tile. What is commonly referred to as "ceramic tile" is usually stoneware, which is a type of ceramic made from gray clay. Stoneware ceramics are fired in a kiln at a higher temperature than terra cotta, making them stronger. Stoneware tiles are often glazed, which gives the tile a colorful, protective coating. Glazed stoneware tiles are usually double-fired in a kiln, making them stronger than unglazed tiles.

• Terra cotta tile. Terra cotta is the cheapest and most fragile variety of ceramic tiles. Commonly used for clay flower pots, terra cotta is orange-red and is often laid without glaze, which makes it highly absorbent of stains, water and other spills.

• Mexican or "Saltillo" tile. This type of tile is made from terra cotta, but is sun-dried instead of baked in a kiln.

• Quarry tile. Contrary to their name, these tiles do not come from quarried stone but rather are unglazed ceramic tiles. Because they are unglazed, your tile contractor will seal them to prevent water absorption and staining, which costs an extra $100 to $400.

• Porcelain tile. Porcelain is the white clay used to make fine china dishes and toilets. A tile must be tested for its durability and low water absorption rate by the Porcelain Tile Certification Agency (PTCA) to be certified as "porcelain." Certified porcelain tile can cost nearly twice as much as regular ceramic tile.

• Natural stone tile. Cut stone tiles are strong and durable with pleasing color variations, but they need to be sealed to prevent staining or water damage.

• Cement tile. Poured into molds, cement tiles can be customized with coloring agents.

• Terrazzo tile. These Italian tiles are made from a cement base mixed with stone or marble chips to create a textured and varied surface.

• Glass tile. Glass tiles are pieces of glass cut into uniform shapes that are bright and translucent. Glass tiles are often used as part of a mosaic pattern for backsplashes and wall tiles, but can also be sold as smaller, individual pieces. Glass tile is generally not used for flooring.

• Mosaic tile. Mosaic tiles can be made from ceramic, glass or metal tiles, and then mounted on mesh backing for easy installation.

Trying to price out tile can be a little overwhelming. Here's a rundown of different kinds of tile flooring and how much the tiles cost (before installation).

Time for the really technical stuff – tile ratings and porosity. Floor tiles have different classifications based on their strength and durability. In addition to the style and appearance factors mentioned in the previous section, both tile ratings and tile porosity have an impact on the overall tile cost.

Not every tile is good for every surface. For example, your high-traffic front entryway needs stronger, more durable tiles than your low-traffic shower floor. Tiles are rated in five classes, with Class V being the most durable and Class I too fragile for flooring. An experienced tile installer can make recommendations on the best tile product for your application.

• Class V tile. Heavy-duty tile approved for commercial and institutional flooring. It can be installed anywhere in a residential environment.

• Class IV tile. This class is good for any residential use (without looking like the floor at a school or a hospital, like Class V).

• Class III tile. Good for residential areas with a normal amount of foot traffic, it can also be used for walls and countertops.

• Class II tile. These tiles are for residential areas with light foot traffic, such as bathrooms.

• Class I tile. Wall tiles only. They are not durable enough for any amount of foot traffic.

A tile's porosity indicates how many air pockets it has. The more porous the tile, the more absorbent it is – which could be good or bad, depending on where it's installed. Tile porosity is rated according to what degree it is “vitreous” or glass-like. Glass being the least absorbent. Here are the porosity classifications of tile:

• Non-vitreous tile. Bisqueware and terra cotta are not glass-like at all. This is the most absorbent type of tile; usually used as decorative or wall tile. Average cost per square foot: $1 to $5

• Semi-vitreous tile. This type of tile is most common for residential applications outside the bathroom. Average cost per square foot: $2 to $6

• Vitreous tile. This type is good for most areas inside the bathroom, except for the shower. Keep in mind that a glazed tile is resistant to water on its surface but not on its sides or back. Continued or repeated exposure to water could affect these tiles over time. Average cost per square foot: $4 to $8

• Impervious tile. This is the least porous tile and is well-suited for high-moisture indoor areas such as baths and showers. Average cost per square foot: $5 to $10

Backsplash installation can cost between $10 and $40 per square foot. So, say you wanted a 25-square-foot kitchen backsplash. The tile installation cost will be between$425 and $900. Backsplashes typically cost more than tile floor installation, to account for the smaller project size.

Pros say new tile is the number one feature homeowners should plan to spend extra money on during a remodel. Tile flooring always adds value to your home due to long term durability. A few tile tips:

• Trendy patterned or metallic tiles can make a big statement, but if you're really looking to increase resale value, stick with classic tile and grout colors that appeal to most buyers.

• Subway tiles have long been popular for bathrooms and kitchens, but new trends are emerging with equally classic shapes like hexagons and herringbone patterns.
• Neutral colors consistently have the best resale value and offer the most versatility for paint and decor.

If you are working on a larger kitchen or bathroom remodel, it's likely that your general contractor will hire a tile installation pro as one of their subcontractors. However, if this is an isolated job or you are acting as your own project manager, the task falls to you to find an experienced tile worker. The first step is to research local pros and narrow it down to a few that fit your needs.

Some states require that the pro have a contractor's license specific to tile and mosaic work. For example, California's Department of Consumers Affairs Contractors State License Board requires anyone who is hired to do more than $500 of tile work on one project to hold a C-54 Ceramic and Tile Mosaic Contractors License. Not all states require such licensing, so be sure to do you research (check that the contractor is insured, too).

Next, ask two to three pros to come out and provide you an exact quote for your job. When scheduling the visit, tell them the square footage of your project and the size and type of tile you will be installing. Be sure to specify whether you need guidance on selecting tile or want them to order the tile on your behalf.

Tile contractors will quote you a price based on the square footage of the project, any prep or repair work required prior to installation, the complexity of the installation and tile pattern, regional labor costs, and materials costs.

Most contractors will remove existing tile or carpet and other non-tile materials before installing new tile, but that labor should be negotiated into the contract. Tile installers generally provide the installation materials needed. Either clients or the tile installation company can provide the tiles.

Once you've accepted a bid, make sure you have a clearly written contract that:

• Indicates which materials are and are not included in the cost.
• States the timeframe for project completion.
• Specifies what responsibilities fall under the tile pro's scope of work.